Tire.



C. M. GRIFFIN.

TIRE.

APPLICATION FILED MAR. 31, 1911.

Patented Sept. 2, 1913 2 SHEETS-SHEET 2.

:Err: I

witwassen MK CHARLES M. GRIFFIN, 0F INDIANAPOLIS, INDIANA, ASSIGNOR TOCHARLES M. GRIFFIN MD HMFY Ci'. CMWFOIRB, .A GQPAMTNEBSHIP.

TIRE.

Specification of Letters Patent.

Application led Marchl, 1911.

To all 'whom t may concern:

Be it known that I, CHARLES M. GRIFFIN, a citizen of the United States,residing at Indianapolis, in the county of Marion and State of Indiana,have invented a new and useful Tire, of which the following is aspecification.

The object of my invention is to produce a tire for vehicle wheels inwhich the desired resiliency shall be obtained b means of aresilientspiral the ends of W ich are so connected to each other thatprovision is made for the necessary relative movement of said ends underaction' provision also being made for facilitating the relative movementof the layers of the spiral under action.

The accompanying drawings illustrate my Invention.

Figure 1 is a side elevation of a tire constructed in accordance with myinvention; Fig. 2 a vertical section transverse to the axis, theresilient spiral being considerably exaggerated in radial dimens1on;Fig. 3 a transverse section about half size; Fig, 4.a fragmentary planof the adjacent ends of the spiral showing one desirable form ofconnectionv between the adjacent ends of the spiral; Fig. 5 a section online 5--5 of Fig.

4; Fig. 6 a plan, similar to Fig. 4, showing similar to Fig. 4 showinganother form ofy connection.

Inthe drawings, 10 indicates an inclosing or casing member which may beof any desii-ed material but conveniently in the general form of anordinary outer casing such as is commonll in use in pneumatic tires.Firmly secure to the edges of this casin are stiff metal rings 11, 1lwhich are pre erably L-'shaped in cross section to insure stiffness. Therings 11 may be suitably formed for connection to the rim 12 of anydesired wheel and, as the particular conformation of these rings forfastening purposes will depend upon the shape of wheel rim to which mytire is to be applied, I shall not attempt to describe the same infurther detail.

-Located within the casing 10 is a metal spiral 14 formed of acomparatively thin resilient band or ribbon wrapped into a spiral. Thematerial from which this ribbon is made may be varied although in prac`tice I have found a tine grade of spring steel to be entire]satisfactory, the ribbon being about 3 wir e for a 4 tire and about 3/32thick. It is to be understood however that the exact dimensions of theribbon will var with circumstances. The ribbon is of suoli length as tomake several convolutions and the two ends are then connected togetherby a yielding means which will permit some relative p ay of these endswhen the device is in use. I consider that it is absolutely essentialthat the connecting means between the two ends of the spiral have theyielding characteristic which I have just mentioned because, inpractice, I found that, when the wheel is subjected to use, the forceacting upon the spiral travels around the s iral at a l times actingsubstantially norma to the spiral, and this causes a shifting of thevariin diameter to serve as a distending force for the outer casing. Ifthe two ends of the spiral are rigidly connected the spiral becomes toostitl" and inelastic and in practice I have found it impossible to makea solid connection between the ends of the spiralof such character as towithstand the great forces resulting from the relative movement of thetwo ends, and that it `is therefore impossible to practically maintain arigid connection between the' two ends of the Spiral.

It will be readily understood that many variations of form of connectionbetween the two ends of the spiral may be had which will rovide thenecessary yieldinrr connection etween the said ends while at the sumetime coming entirely within the spirit of the invention and I havetherefore shown in the drawings three different forms ofsuch connectionwhich I believe to be practical.

In Figs. 4 and 5 the inner end 14 of the J band or ribbon 14 has securedto its inner face a pair of brackets 21, 2l connected by a pin 2l. Onthis in 21 are ivoted two rods 22, 22, the ro s being hel separated by aspring 23 which surrounds pin 21 and 25 and the block 24 is a spring 27.Secured to the outer end 14 of the band 14 1s a hook 28 which isprojected through suitably formed slots 29, the several slots being.

made of 4increasing length to take care of the difference in movement ofthe various layers. The hook 28 is projected into position to serve asan abutment for block 24 in one direction, the springs 27 holding theparts in place.

In operation the spiral 14 is placed within the casing 10 and the casingis either internally formed to make a seat for the spiral, or an annularseat pad 32 is intro-duced between the spiral and casing as shown inFig. 3. Thereupon, by tightening the nuts 25 so as to draw the rods 22through the block 24, the ends of the spiral may be drawn toward eachother in opposite directions so as to increase the diameter of thespiral and thus place the casing 10 under such tension as may be desiredbetween the two rings 11. Vhenever the wheel is subjected to a loa-dthere will be a distortion of the spiral immediately adjacent the groundwhich will tend to shift one end of the spiral relative to the other andthis shifting is permitted by reason of springs 27.

In the form shown in Figs. 6 and 7 the outer tip 14 of the ribben 14 isprovided with a pin or standard 41 which is projected through slots 29in the various layers of the spiral and pivotally connected to the innerend of this standard is a flexible connector which is convenientlyformed by a link belt. The forward links of this connector 42 areprovided with cross pins 43 any one of which maybe placed in` a pair ofhooks 44 secured to the inner tip 14 of the ribbon 14. With this formthere is sufcient flexibilityA of the connector between the hooks 44 andthe pin 41 to permit necessary relative movement of the two ends of thespiral under action.

In the form shown in Fig. 8 the Y-shaped connector 51 has its-two armsprojected througha block 24', like block 24, and the ends of the armsare provided with'nuts 52.

with springs 53 between said nuts and the block 24. The stem of theconnector 51 is threaded along its major portion and passes freelythrough the bracket 21" which in most particulars corresponds to bracket21 of the form shown in Fig. 5, a nut being threaded upon the projectedend of the stem of the connector. A hook1 28 coperates with the block 24in the same way as does the hook 28 with the block 24 in the form shownin- Fig. 5.

In view of the relative movement of the various convolutions of thespiral, when the device is in action, vit is desirable that a lubricantbe maintained between the various convolutions and for this purpose Ibelieve that a dry lubricant like occulent graphite lis' preferableespecially as such a lubricant does not have any deleterious effectslupon the outer casing when the outer casing is made of rubber. In orderto facilitate the movement of the lubricant between the variousconvolutions of the spiral I have found it advisable to occasionallyperforate the spiral, asindicated at 55.

Iv claim as my invention: f

1. A resilient tire comprising an outer casing, rigid rings secured tothe opposite edges of said casing, a resilient spiral comprising two ormore complete turns arranged within said casing to-expand the samebetween the rings, vand an adjustable circumferentially-yieldingconnection between the ends of said spiral.

2. A resilient tire comprisingv an outer casing, rigid rings secured tothe opposite edges of said casing, a resilient spiral comprising two :ormore complete turns arranged within said casing to expand the samebetween the rings, a member carried by the outer end of said spiral andprojected through elongated slots in the adjacent convolutions, and anadjustable circumferentially-yielding connector connecting the inneryend of said spiral and said inwardly projecting member.

3. A resilient tire comprising an outer casing, means for firmly holdingthe edges of said casing, a resilient spiral arranged within said casingto expand the same at its middle, and an adjustable connector betweenthe ends of the spiral by which the `spiral may be expanded, saidadjustable connector embodying-a sprlng opposing decrease of diameter ofthe spiral.

In witness whereof, I have hereunto set my hand and seal at Sheboygan,Wisconsin, this 25th day of March, A. D. one thousand nine `hundred andeleven.

CHARLES M. GRIFFIN.

Witnesses:

FELIX BENrnY, ALLEN I). YOUNG.

